Truck weighing stations need to be tested periodically to ensure their accuracy. Such stations include those along highways maintained by state highway departments to determine compliance with vehicular weight restrictions and those weigh stations at industrial plants which are used to determine the weight of truck deliveries. Most states require that the scales alongside highways be calibrated at periodic intervals. The testing of these scales consists of placing known weights weighing several thousand pounds at specified locations on the scale platform and calibrating the scale by comparing the actual weight to the indicated weight. Adjustments in read-out then can be made to accurately reflect the known weight. Ten to twenty thousand pounds is a commonly used known weight for each scale testing.
Most states have employed a traveling staff who carry along weights to the various scales and then place those weights upon the platform to calibrate the scales. To facilitate this testing, there is a need for trucks which carry the standard weights between stations and quickly lift them on and off the scale for testing.
Trucks currently used have been relatively slow in depositing and picking up the weights from the scale. These have generally used an electric hoist which raises and lowers weights suspended from a cable and have used electric motor driven means to move the hoist into or out of the truck bed for moving the weights. In addition, the weight have been supported in a manner which requires the operator to move from the controls to manually attach or disengage the weights from the cable. All of these features have caused prior mechanisms to be relatively slow in loading and unloading the weights.
The present invention is directed to overcoming one or more of the problems as set forth above.